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Rafael J. Wysockia9d70522009-06-10 01:27:12 +02001/*
2 * kernel/power/suspend.c - Suspend to RAM and standby functionality.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
7 *
8 * This file is released under the GPLv2.
9 */
10
11#include <linux/string.h>
12#include <linux/delay.h>
13#include <linux/errno.h>
14#include <linux/init.h>
15#include <linux/console.h>
16#include <linux/cpu.h>
17#include <linux/syscalls.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090018#include <linux/gfp.h>
Matthew Garrettdd4c4f12010-05-28 16:32:14 -040019#include <linux/io.h>
20#include <linux/kernel.h>
21#include <linux/list.h>
22#include <linux/mm.h>
23#include <linux/slab.h>
24#include <linux/suspend.h>
Rafael J. Wysockia9d70522009-06-10 01:27:12 +020025
26#include "power.h"
27
28const char *const pm_states[PM_SUSPEND_MAX] = {
29 [PM_SUSPEND_STANDBY] = "standby",
30 [PM_SUSPEND_MEM] = "mem",
31};
32
33static struct platform_suspend_ops *suspend_ops;
34
35/**
36 * suspend_set_ops - Set the global suspend method table.
37 * @ops: Pointer to ops structure.
38 */
39void suspend_set_ops(struct platform_suspend_ops *ops)
40{
41 mutex_lock(&pm_mutex);
42 suspend_ops = ops;
43 mutex_unlock(&pm_mutex);
44}
45
46bool valid_state(suspend_state_t state)
47{
48 /*
49 * All states need lowlevel support and need to be valid to the lowlevel
50 * implementation, no valid callback implies that none are valid.
51 */
52 return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
53}
54
55/**
56 * suspend_valid_only_mem - generic memory-only valid callback
57 *
58 * Platform drivers that implement mem suspend only and only need
59 * to check for that in their .valid callback can use this instead
60 * of rolling their own .valid callback.
61 */
62int suspend_valid_only_mem(suspend_state_t state)
63{
64 return state == PM_SUSPEND_MEM;
65}
66
67static int suspend_test(int level)
68{
69#ifdef CONFIG_PM_DEBUG
70 if (pm_test_level == level) {
71 printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
72 mdelay(5000);
73 return 1;
74 }
75#endif /* !CONFIG_PM_DEBUG */
76 return 0;
77}
78
79/**
80 * suspend_prepare - Do prep work before entering low-power state.
81 *
82 * This is common code that is called for each state that we're entering.
83 * Run suspend notifiers, allocate a console and stop all processes.
84 */
85static int suspend_prepare(void)
86{
87 int error;
88
89 if (!suspend_ops || !suspend_ops->enter)
90 return -EPERM;
91
92 pm_prepare_console();
93
94 error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
95 if (error)
96 goto Finish;
97
98 error = usermodehelper_disable();
99 if (error)
100 goto Finish;
101
102 error = suspend_freeze_processes();
103 if (!error)
104 return 0;
105
106 suspend_thaw_processes();
107 usermodehelper_enable();
108 Finish:
109 pm_notifier_call_chain(PM_POST_SUSPEND);
110 pm_restore_console();
111 return error;
112}
113
114/* default implementation */
115void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
116{
117 local_irq_disable();
118}
119
120/* default implementation */
121void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
122{
123 local_irq_enable();
124}
125
126/**
127 * suspend_enter - enter the desired system sleep state.
128 * @state: state to enter
129 *
130 * This function should be called after devices have been suspended.
131 */
132static int suspend_enter(suspend_state_t state)
133{
134 int error;
135
136 if (suspend_ops->prepare) {
137 error = suspend_ops->prepare();
138 if (error)
139 return error;
140 }
141
142 error = dpm_suspend_noirq(PMSG_SUSPEND);
143 if (error) {
144 printk(KERN_ERR "PM: Some devices failed to power down\n");
145 goto Platfrom_finish;
146 }
147
148 if (suspend_ops->prepare_late) {
149 error = suspend_ops->prepare_late();
150 if (error)
151 goto Power_up_devices;
152 }
153
154 if (suspend_test(TEST_PLATFORM))
155 goto Platform_wake;
156
157 error = disable_nonboot_cpus();
158 if (error || suspend_test(TEST_CPUS))
159 goto Enable_cpus;
160
161 arch_suspend_disable_irqs();
162 BUG_ON(!irqs_disabled());
163
164 error = sysdev_suspend(PMSG_SUSPEND);
165 if (!error) {
166 if (!suspend_test(TEST_CORE))
167 error = suspend_ops->enter(state);
168 sysdev_resume();
169 }
170
171 arch_suspend_enable_irqs();
172 BUG_ON(irqs_disabled());
173
174 Enable_cpus:
175 enable_nonboot_cpus();
176
177 Platform_wake:
178 if (suspend_ops->wake)
179 suspend_ops->wake();
180
181 Power_up_devices:
182 dpm_resume_noirq(PMSG_RESUME);
183
184 Platfrom_finish:
185 if (suspend_ops->finish)
186 suspend_ops->finish();
187
188 return error;
189}
190
191/**
192 * suspend_devices_and_enter - suspend devices and enter the desired system
193 * sleep state.
194 * @state: state to enter
195 */
196int suspend_devices_and_enter(suspend_state_t state)
197{
198 int error;
Rafael J. Wysocki452aa692010-03-05 13:42:13 -0800199 gfp_t saved_mask;
Rafael J. Wysockia9d70522009-06-10 01:27:12 +0200200
201 if (!suspend_ops)
202 return -ENOSYS;
203
204 if (suspend_ops->begin) {
205 error = suspend_ops->begin(state);
206 if (error)
207 goto Close;
208 }
209 suspend_console();
Rafael J. Wysocki452aa692010-03-05 13:42:13 -0800210 saved_mask = clear_gfp_allowed_mask(GFP_IOFS);
Rafael J. Wysockia9d70522009-06-10 01:27:12 +0200211 suspend_test_start();
212 error = dpm_suspend_start(PMSG_SUSPEND);
213 if (error) {
214 printk(KERN_ERR "PM: Some devices failed to suspend\n");
215 goto Recover_platform;
216 }
217 suspend_test_finish("suspend devices");
218 if (suspend_test(TEST_DEVICES))
219 goto Recover_platform;
220
221 suspend_enter(state);
222
223 Resume_devices:
224 suspend_test_start();
225 dpm_resume_end(PMSG_RESUME);
226 suspend_test_finish("resume devices");
Rafael J. Wysocki452aa692010-03-05 13:42:13 -0800227 set_gfp_allowed_mask(saved_mask);
Rafael J. Wysockia9d70522009-06-10 01:27:12 +0200228 resume_console();
229 Close:
230 if (suspend_ops->end)
231 suspend_ops->end();
232 return error;
233
234 Recover_platform:
235 if (suspend_ops->recover)
236 suspend_ops->recover();
237 goto Resume_devices;
238}
239
240/**
241 * suspend_finish - Do final work before exiting suspend sequence.
242 *
243 * Call platform code to clean up, restart processes, and free the
244 * console that we've allocated. This is not called for suspend-to-disk.
245 */
246static void suspend_finish(void)
247{
248 suspend_thaw_processes();
249 usermodehelper_enable();
250 pm_notifier_call_chain(PM_POST_SUSPEND);
251 pm_restore_console();
252}
253
254/**
255 * enter_state - Do common work of entering low-power state.
256 * @state: pm_state structure for state we're entering.
257 *
258 * Make sure we're the only ones trying to enter a sleep state. Fail
259 * if someone has beat us to it, since we don't want anything weird to
260 * happen when we wake up.
261 * Then, do the setup for suspend, enter the state, and cleaup (after
262 * we've woken up).
263 */
264int enter_state(suspend_state_t state)
265{
266 int error;
267
268 if (!valid_state(state))
269 return -ENODEV;
270
271 if (!mutex_trylock(&pm_mutex))
272 return -EBUSY;
273
274 printk(KERN_INFO "PM: Syncing filesystems ... ");
275 sys_sync();
276 printk("done.\n");
277
278 pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
279 error = suspend_prepare();
280 if (error)
281 goto Unlock;
282
283 if (suspend_test(TEST_FREEZER))
284 goto Finish;
285
286 pr_debug("PM: Entering %s sleep\n", pm_states[state]);
287 error = suspend_devices_and_enter(state);
288
289 Finish:
290 pr_debug("PM: Finishing wakeup.\n");
291 suspend_finish();
292 Unlock:
293 mutex_unlock(&pm_mutex);
294 return error;
295}
296
297/**
298 * pm_suspend - Externally visible function for suspending system.
299 * @state: Enumerated value of state to enter.
300 *
301 * Determine whether or not value is within range, get state
302 * structure, and enter (above).
303 */
304int pm_suspend(suspend_state_t state)
305{
306 if (state > PM_SUSPEND_ON && state <= PM_SUSPEND_MAX)
307 return enter_state(state);
308 return -EINVAL;
309}
310EXPORT_SYMBOL(pm_suspend);